Epidemiologic Studies of Fecal Mutagenicity, Cooked Meat Ingestion, and Risk of colorectal Cancer
Laboratory studies have demonstrated the carcinogenic potential of heterocyclic amines found in cooked meats. Epidemiologic studies are needed to define the risk to humans of low-level, chronic ingestion of these compounds. Based on epidemiologic studies to date, the leading candidate for a human tumor that could be related to cooked meat consumption is colorectal cancer. This chapter examines the fecal mutagenicity as a possible biomarker of "effective dose" of dietary genotoxins, and discusses the findings from a case-control study of colorectal cancer. Familial influences on susceptibility to colorectal cancer occurrence have been documented for common sporadic tumors as well as for the rare familial polyposis syndromes in which nearly all affected members develop colorectal cancer. In an investigation limited by small percentages of mutagenic samples, we have observed an association between colorectal cancer risk and nonfecapentaene mutagenicity, detected in acetone-based fecal extracts by Salmonella tester strain TA98 without S9 activation.